In order to reduce the burden of a driver in driving a vehicle, there is a steering assistance control device including, as an additional function, the automatic steering operation of detecting the position and shape of a white line with devices, such as radar, a camera, a navigator, and an in-vehicle communication device, and applying steering torque to electric power steering to keep in a traffic lane.
For the calculation of the steering torque in the steering assistance control device, a calculation is typically made with, for example, PID control on the basis of the middle position in a traffic lane and the position and orientation of a host vehicle.
The following technique in the steering assistance control device has been known. In accordance with a previously detectable road environment, such as the shape of a road or construction, with in-vehicle devices, such as GPS and a camera, the middle position in the traffic lane being a goal is offset to perform control (e.g., refer to PTL 1).
In order to prioritize steering of the driver in the steering assistance control device, there is a technique of releasing steering assistance control in a case where intervention of the steering of the driver has been detected. The intervention of the steering of the driver may be determined in a case where a steering angle, a steering angle velocity, and the value of a steering torque sensor each have exceeded a driver steering intervention threshold value (e.g., refer to PTL 2 and PTL 3 below).